I've played about 45 hours so far just exploring and having a good time. I have all 3 vehicles, a bunch of materials, and a nice base a little east of the safe shallows overlooking the grassy plateaus.

I've already repaired the aurora, watched the sunbeam explode, explored jellyshroom cave and degasi habitat there, and fully explored both island land masses. Also came across a few alien gateways in my travels but no idea how to activate them or what they're for.

My last radio message was from Lifepod 2. I noticed it's right outside a cave system with an acidic base (is this the lost river everyone keeps talking about?). I was exploring that and discovered a base that was producing warpers and downloaded the data banks in there. After that I got insanely lost in that area and my seamoth was dangerously low on charge, but I found my way back to my base.

But now there's no more radio messages. I do notice some things I want to craft have materials I don't have such as nickel. I keep feeling like I missed something but I don't want to look up a guide. Just wondering if anyone can toss me a clue. Is there more than 1 base in that lost river area?